The present invention generally relates to recording and reproduction of data, and more particularly relates to a technique of continuously recording and reproducing AV data in a system, like a disk changer, in which a plurality of storage media can be housed.
Various types of storage media, including hard disk, optical disk, floppy disk and semiconductor memory, have been used for storing digital data thereon. Among these media, an optical disk has been used most frequently as a medium for storing recyclable digital data thereon, because an optical disk is advantageous in portability and capacity. Also, in most cases, the data stored on such a storage medium has been of a small size, e.g., text data or still picture data on the order of several tens megabytes.
However, in recent years, the demand for a storage medium that can store data of a much greater size, like moving picture data on the order of several gigabytes, has been increasing day after day. In recording such an enormous quantity of data, however, a single storage medium can rarely meet the capacity required for recording the data entirely. The same is true of even a large-capacity storage medium such as a DVD-RAM.
For example, as for a laser disc (LD), if data cannot be recorded entirely on a single side thereof, then the data is separately recorded on both sides thereof to avoid the problem of insufficient capacity. On the other hand, a recording/reproducing apparatus using a disk changer compensates for the shortage of capacity by recording data on a plurality of disks.
Regarding text data or still picture data, the recording and reproducing operations thereof do not have to be performed in real time. Accordingly, there is no problem if such data is recorded on a plurality of disks separately so long as disks are exchanged every time data has been written on a single disk.
However, if moving picture data is recorded in real time on both sides of an LD or on a plurality of disks, then it is difficult to maintain satisfactory continuity for the data stored. Specifically, in reproducing data stored on different disks or different sides, it takes a rather long time to reverse the side to be reproduced from recto into verso or to exchange the disks to be reproduced. Accordingly, the reproduction of the data may be discontinued because such an operation of reversing the side or exchanging the disks should be performed. Similarly, in recording data on different disks or different sides, the supply of the data must be suspended while the side to be recorded is reversed from recto into vero so or while the disks to be recorded are exchanged.